Well control apparatus

ABSTRACT

An assembly for regulating the flow of effluents through a multiple conduit well may comprise: a support assembly for releasably supporting a plurality of conduits in the well; a sensing device connected to the support assembly and responsive to one or more predetermined conditions at the well to automatically release the conduits; and a flow control device connected to each of the conduits and operable upon predetermined movement of it&#39;&#39;s respective conduit to regulate flow of effluents through the well. Upper and lower sections of the conduits may be releasably connected by a connector device adapted to accommodate normal well induced movement of the conduits to prevent induced movement from operating the flow control devices. The flow control device may comprise a subsurface valve assembly including: a first tubular body; a second tubular body telescopically and sealingly engaging the first tubular body; a seat carried by one of the tubular bodies; and a closure member carried by the other tubular body, adapted to move between an open position, allowing flow through the conduit, to a closed position engaging the seat and preventing flow through the conduit, in response to relative axial movement between sections of the conduit. The subsurface valve assembly may include a retrievable valve adapted for axial movement through the conduit for operative engagement with the first and second tubular bodies to prevent movement of the closure member to the closed position, the retrievable valve being movable between open and closed positions in response to relative axial movement between sections of the conduit.

[4 1 Nov. 19, 1974 WELL CONTROL APPARATUS Cicero C. Brown, P.O. Box 19236, Houston, Tex. 77024 [22] Filed: Nov. 29, 1972 [21] Appl. No.: 310,665

[76] Inventor:

[52] US. Cl. 166/72, 166/226 [51] Int. Cl. ..E21b 43/12, E2lb 33/03 [58] Field of Search 166/53, 72, 73, 78, 226, 166/95, 315

[56] References Cited UNITED STATES PATENTS 2,831,539 4/1958 EnDean et a1. 166/73 3,094,170 6/1963 Bourne, Jr. 166/72 3,351,133 11/1967 Clark, Jr. et a1... 166/53 3,731,742 5/1973 Sizer l. 166/72 Primary Examiner-James A. Leppink Attorney, Agent, or FirmTorres & Berryhill [57] ABSTRACT An assembly for regulating the flow of effluents through a multiple conduit well may comprise: a support assembly for releasably supporting a plurality of conduits in the well; a sensing device connected to the support assembly and responsive to one or more predetermined conditions at the well to automatically release the conduits; and a flow control device connected to each of the conduits and operable upon predetermined movement of its respective conduit to regulate flow of effluents through the well. Upper and lower sections of the conduits may be releasably connected by a connector device adapted to accommodate normal well induced movement of the conduits to prevent induced movement from operating the flow control devices.

The flow control device may comprise a subsurface valve assembly including: a first tubular body; a second tubular body telescopically and sealingly engaging the first tubular body; a seat carried by one of the tubular bodies; and a closure member carried by the other tubular body, adapted to move between an open position, allowing flow through the conduit, to a closed position engaging the seat and preventing flow through the conduit, in response to relative axial movement between sections of the conduit. The subsurface valve assembly may include a retrievable valve adapted for axial movement through the conduit for operative engagement with the first and second tubular bodies to prevent movement of the closure member to the closed position, the retrievable valve being movable between open and closed positions in response to relative axial movement between sections of the conduit.

30 Claims, 7 Drawing Figures WELL CONTROL APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of effluents through well structures. More specifically the present invention relates to an assembly suitable for automatically terminating the flow of effluents through well conduits supported from an offshore production platform in the event of fire, explosion, damage to or inoperability of the restraining structures at the wellhead.

2. Brief Description of the Prior Art Many of the prior art safety valves employed in offshore well installations are the self-contained type which close automatically in response to either a drop in pressure of the well efi'luents or to an increase in rate of fluid flow through the well. Valves are positioned at a subsurface location within the well where they are protected from surface damage. The valves are intended to function as safety devices to prevent a blowout in which the well fluids flowing uncontrollably from a damaged well may cause injury to personnel, environmental damage or may ignite and destroy the supporting well structures.

The conventional, self-contained safety valves which close only on the occurrence of either low effluent pressure or an increased rate of effluent flow are impractical to test since it is difficult to simulate the necessary high flow or low pressure conditions within the well. Such self-contained valves may also present problems when it is desired to close the subsurface valve and a wellhead valve simultaneously in anticipation of threatened damage to the wellhead structure, e.g., when a hurricane is eminent. Furthermore, there are many conditions which may occur to the well platform such as fire, wind and collision with ocean going vessels which would not necessarily cause the conventional type subsurface valve to close.

One prior art safety valve which overcomes many of the disadvantages associated with self contained flow responsive or pressure responsive safety valves employs a small diameter macaroni conduit which extends from a subsurface valve to the well s surface. The macaroni conduit contains a pressurized incompressible hydraulic fluid which maintains the valve open. The valve is positively controlled from the wellhead and the loss of pressure in the line automatically releases the closure elements of the subsurface valve, closing the valve and terminating all flow through tubing string. Such a system is disadvantageous in that macaroni conduit strings must be accommodated between the tubing string and surrounding well casing. The requirement for an additional conduit in addition to the casing and tubing string is undesirable in many applications, and a macaroni conduit string, because of its small size, is subject to breakage and crimping which may prevent proper operation of the valve. In addition, the macaroni line and the tubing string must be installed in the well simultaneously and special equipment is required for handling the dual string assembly. I

In recent years subsurface safety valve apparatus has been developed which is operable by vertical movement of the flow tubing to which the valve is attached.

A hydraulic piston and cylinder assembly may be provided by which the flow tubing is normally maintained in an upper position but, which, on release of pressure therefrom, allows the tubing to move downwardly by gravity to close the attached subsurface safety valve.

Recent examples of such subsurface safety valve apparatus may be seen in the following US. Pat. Nos. 3,351,133 Clark, Jr. et al., 3,411,585 Page, Jr., 3,662,824 Page, Jr.

Although such systems do allow operation of a subsurface safety valve without being dependent upon flow effluent pressure or an increased rate of effluent flow, they do not necessarily assure operation of the subsurface safety valve under certain circumstances which may occur at the wellhead.

In my aforementioned copending patent application Ser. No. 210,738 an improved well control means is disclosed in which the flow tubing is employed to regulate opening and closing of a subsurface safety valve. The flow tubing or conduit is supported at the well surface by a structure which is designed to release the conduit in the event of fire or severe physical impact sensed by heat fusible and/or frangible detectors positioned at the wellhead. In one form of the invention, automatic release of the support following fire or impact permits the conduit to fall longitudinally under the influence of gravity to the extent necessary to close the subsurface valve.

In a preferred form of the aforementioned improved well control means, the support structure includes a hydraulic system which provides longitudinal support for the well conduit during normal conditions. The loss of the hydraulic fluid in the system, or a predetermined reduction in pressure of the fluid, permits the well conduit to move longitudinally under the influence of gravity to produce the necessary movement required to close the subsurface valve. The valve may be reopened by repressuring the system to elevate the well conduit.

One complication encountered in such systems is the axial conduit movement induced by normal well conditions, such as changes in the temperature of pressure of the well effluent. Such induced movement,.if not compensated for, may cause the subsurface valve to prematurely open or close. One form of the aforementioned improvement employs a telescoping slip joint to compensate for such normal well condition induced longitudinal elongation and fore-shortening of the conduit to prevent such induced movement from operating the subsurface valve.

SUMMARY OF THE INVENTION The present invention concerns a further improvement in the well control assembly of the aforementioned US. Pat. application Ser. No. 210,738. As in the prior improvement, the assembly of the present invention provides support for the flow tubing or conduit at the well surface which is designed to release the conduit in the event of fire or severe physical impact, permitting the conduit to fall longitudinally under the influence of gravity to the extent necessary to close a subsurface valve connected in the conduit. Although the improved assembly of the prior application may be adapted for use with multiple tubing string wells, it was primarily contemplated for use with a single tubing string. In the present application, an assembly is described specifically for use with multiple conduit wells.

Like in some forms of the improvement discussed in the aforementioned patent application, the assembly of the present invention may utilize a slip joint to compensate for axial conduit movement induced by nonnal well conditions. A specific form of such a slip joint is disclosed in the present application which in addition to providing compensation for normal well condition induced movement, allows separation of an upper section of the flow tubing from a lower section thereof. Such a connector allows replacement or repair of upper components of the well with assurance that the subsurface safety valve will be closed during such operations.

Also disclosed in the present application are specific forms of subsurface safety valves suitable for use with the present system. One valve embodiment described employs a flapper type closure element operated by longitudinal movement of the flow tubing or conduit. A retrievable ball type valve is also disclosed which is adapted to be lowered through the tubing string to operative engagement with the primary subsurface valve in such a manner as to make the retrievable valve operative while rendering the primary valve inoperative to axial movement of the tubing conduit on release of the hydraulic suspension apparatus. Thus, a means is provided for opening or closing the flow conduit when the primary subsurface valve may be damaged or become inoperative for some unforeseen reason.

The foregoing as well as other features and advantages of the present invention will be more readily apparent from the following specification, drawings, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial vertical elevation, partially in section, schematically illustrating a longitudinally movable well control assembly for use with a multiple tubing well, according to a preferred embodiment of the invention;

FIG. 2 is a partial vertical elevation, partially in section, representing the wellhead and tubing support apparatus of the assembly schematically represented in FIG. 1;

FIG. 3 is a vertical quarter section illustrating details in the construction of a flapper type subsurface safety valve assembly for use with the system schematically illustrated in FIG. 1;

FIG. 4 is a vertical quarter section illustrating a retrievable ball type safety valve adapted for operative engagement with the flapper type safety valve of FIG.

FIG. 5 is a vertical quarter section illustrating a combination slip joint and connector assembly, in the latched-in position, suitable for use with the system illustrated in FIG. 1;

FIG. 6 is a vertical quarter section illustrating the combination slip joint and connector assembly of FIG. 5 in the unlatched condition; and

FIG. 7 is a vertical quarter section of a combination slip joint and connector assembly, according to an alternative embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 of the drawings there is schematically illustrated an exemplary form of the well control system of the present invention. The well includes a wellhead W conventionally comprising casing head C, tubing head T, master valves V swab valves V and wing valves V,,.. Casing access valves V may also be employed. Although the wellhead W may represent the wellhead of a well completed at any location, onshore or offshore, it is contemplated that the control system of the present invention will find its greatest use in an offshore well in which the wellhead W is supported on a platform (not shown) above a body of water.

Supported by the wellhead W in a manner to be described hereafter is a plurality of tubing strings or flow conduits T and T At the upper end of each flow conduit T T is a hydraulic suspension assembly 10, 11, respectively, by which the strings are supported within the casing 12 of the well. The lower end of the tubing strings, T and T are attached to packers l3 and 14 by which the lower end of the tubing strings are anchored in the well for communication with lower and upper zones of production. The production zone from which fluids pass through conduit T, lies below packer l3 while the upper production zone, from which fluids pass through conduit T lies between packers l3 and 14. Each of the conduits T T is equipped with a subsurface safety valve indicated generally at 15 and 16, respectively, which are employed to regulate the flow of well effluents through the production tubing strings T and T Of course the master valves V,,,, wing valves V,,, and swab valves V, at the wellhead W are also used in controlling the flow of effluents from the tubing strings T and T Each of the tubing strings T and T may also be equipped with a slip joint or connector generally designated at 17 and 18. These slip joints, as will be more fully understood hereafter, provide a means for com pensating the well movements induced by normal well conditions. As will also be more fully understood hereafter, these slip joints 17 and 18 may also provide a means by which upper sections of the tubing strings T, and T may be removed from the well without disturbing lower sections thereof and automatically closing the subsurface safety valves 15 and 16.

Referring now, in addition to FIG. 2, the further details of the wellhead W and hydraulic suspension assemblies 10 and 11 will be described. The casing head C may be supported by a surface casing 20 in a conventional manner. The casing head C may provide support for the production casing 12 which generally extends from the surface of the wells to the production zones. The casing 12 may be supported in a conventional manner by a casing hanger 21 having conventional slips and sealing components. The casing head C may be surmounted by a tubing head T and provided with a conventional packoff 22 for sealing between the tubing head T and casing 12.

A pair of tubing nipples 23 and 24 may be supported in the tubing head T by a pair of tubing hangers 25 and 26. The tubing hangers 25 and 26 are provided with suitable sealing elements 25a and 26a for sealing between the tubing hangers 25 and 26 and the tubing head T and tubing nipples 23 and 24. Holddown screws 25b and 26b may be provided for holding tubing hangers 25 and 26. A pair of hydraulic conduits 27 and 28 may be connected to corresponding ports in the tubing head T for registration with annular recesses 29 and 30 provided in each of the tubing hangers 25 and 26. Suitable seals 31 and 32 may also be provided to isolate these hanger recesses. The hydraulic conduits 27 and 28 may be connected to a source hydraulic fluid from a pressurizing system (not shown) for automatically maintaining a constant control pressure on the hydraulic fluid for a purpose to be explained.

The pressurizing system supplies hydraulic fluid through the conduits 27 and 28 to automatically maintain a constant control pressure on the hydraulic fluid for a purpose to be explained. The system may comprise supply lines connected to suitable regulators and pumps and a fluid reservoir. The details of such a system are fully explained in the aforementioned US. Pat. application Ser. No. 210,738 and reference may be made to such application for a fuller understanding of the operation thereof. For present purposes it is sufficient to know that such a pressurizing system supplies a constant control pressure fluid to the recesses 29 and 30, as long as normal conditions exist. Should at abnormal condition occur, such as fire, or collision with an ocean going vessel, suitable sensors connected to the pressurizing system will automatically cause the pressure of the control fluid to be substantially reduced, the effect of which will be to release the hydraulic suspension assemblies and 11, allowing the tubing strings T and T to move downwardly under the influence of gravity causing valves and 16 (see FIG. 1) to close.

Each of the hydraulic suspension assemblies may comprise a hydraulic cylinder 33 and 34 attached to a respective tubing nipple 23 or 24 by a conventional pin and box connection 35, 36 respectively. Telescopically received within cylinders 33 and 34 for limited axial movement therein is a pair of tubular piston members 37 and 38. The piston members 37 and 38 are attached to and may be considered as forming the upper portions of tubing strings T and T In the embodiment shown in FIG. 2, cylinders 33 and 34 are divided into a pair of chambers 39 and 40, 41 and 42 by annular shoulders 43 and 44. Each of the piston members 37 and 38 may then be provided with a pair of annular pis ton heads 45 and 46, 47 and 48 for sliding engagement with the walls of the respective chambers within which they are disposed. Suitable seals are provided between the cylinders 33 and 34 and piston assemblies 37 and 38 for sliding sealing engagement therebetween. The upper end of each cylinder chamber is vented by vent ports 49, 50, 51 and 52 so that the upper annular surfaces of piston heads 45, 46, 47 and 48 are subjected only to the pressure within casing 12, normally a low value.

The lower ends of the cylinder chambers are connected through suitable ports 53, 54, 55, and 56 to fluid conduits 57 and 58 which are in turn connected to recesses 29 and in the tubing hangers 25 and 26. Thus, the lower side of the annular piston heads 45, 46, 47 and 48 are subjected to the pressure in the pressurizing system heretofore referred to. As long as the pressure in the pressurized fluid system remains at a sufficient level the force applied to pistons 37 and 38, and consequently tubing strings T and T is sufficient to maintain the tubing strings in an upwardly displaced position. Of course only one chamber and one annular pistonhead may be utilized in each of the hydraulic suspension systems 10 and 11. However, with the dual arrangement illustrated in FIG. 2 the support force is essentially twice as great.

Under normal conditions the piston assemblies 37 and 38 are supported in an upwardly displaced position maintaining the valves 15 and 16 in an open condition and permitting the flow of effluents through the tubing strings T T to the wellhead W. However, when an abnormal condition is sensed by the pressurized system previously referred to, the fluid pressure therein is reduced by a substantial amount reducing the force supporting the pistons 37 and 38 and their respectively attached tubing strings T,, T releasing the same for downward movement under the influence of gravity. A downward movement of a predetermined amount will cause the valves 15 and 16 to close preventing further flow of effluents from the well. It will be appreciated that while the specific exemplary pressurized fluid system described in the aforementioned U.S. Pat. application Ser. No. 210,738 is suitable for use with the present invention, any conventional or well known means for automatically maintaining a predetermined pressure value in the supply lines 27 and 28 may be employed. In addition, while specific fire and impact sensors have been mentioned for remotely releasing pressure in the hydraulic system, any suitable means for automatically releasing or reinitiating pressure in the system by command signals generated from a remote location may be employed.

Referring now to FIG. 3, a specific valve assembly, suitable for use with the present invention, will be described. The valve represents the valve 15 connected to tubing string T in FIG. 1, it being understood that valve 16 could be identical. The valve 15 comprises, in general, composite outer tubular body 60 in which is telescopically received an inner tubular body 61. Tubular body 60 may be formed from upper and lower tubular sections 62, 63, respectively, and intermediate sections 64 and 65. The various sections are connected by suitable means such as'threaded connections 66, 67, and 68 and are provided with seals 69, 70 and 71 malting such connections fluidtight. Upper section 62 is provided with internal threads for a pin and box connection 72 with tubing string T Upper section 62 is also provided with internal annular shoulders 73 and 74 forming an annular recess 75 therebetween, the purpose of which will be described hereafter. The internal diameter of intermediate section 64 is substantially less than the internal diameter of the adjacent sections 62 and 65 so as to form a recess 76 in which is mounted a flapper or valve closure member 77. The flapper is attached by a hinge or pivot connection 78 and is biased away from the recess 76 by spring 79.

Inner tubular member 61 may be attached by a threaded connection 80 to adaptor 81 for connection with a lower section of tubular string T Inner tubular body 61 normally remains in a fixed position with the portion of the tubing string T therebelow and the anchoring means (13 and 14 in FIG. 1) by which the lower portion of the tubing string is fixed ih the well.

An annular stop shoulder 87 and annular recess 88, the purposes of which will be understood hereafter, are provided on the interior of inner tubular body 61. Also provided on the interior of inner tubular body 61 is an annular seating surface 89 for engagement by the closure member 77, as will be explained hereafter. Just below the annular seating surface 89 a portion of the wall of inner tubular body 61 is removed to provide an access 90 for entry of flapper 77.

Outer tubular body 60 surrounds the inner tubular body 61 in a telescopic sliding fit. A spline or longitudinal slot 82 may be provided on the exterior of inner tubular body 61 for engagement by a guide pin 83 attached to the lower section 63 of the outer tubular body 60. This allows relative axial movement between the outer and inner tubular bodies 60 and 61, respectively, but prevents relative rotation therebetween. Thus a torque may be transmitted from the surface of the well through the valve 15. Seals 84, 85 and 86 assure a sliding sealing fit between the tubular bodies 60 and 61.

Under normal conditions the valve 15 is maintained in the open position shown in FIG. 3, allowing effluents to flow unrestricted through the tubing string T to the surface of the well. Should an abnormal condition occur which releases the hydraulic suspension means 10, previously discussed with reference to FIG. 2, the portion of tubing string T above valve 15 will drop downwardly under the influence of gravity. As the above portion of tubing string T drops downwardly, so does outer tubular body 60 drop downwardly relative to inner tubular body 61. In so doing, flapper 77 also moves downwardly to a position adjacent access 90. Since the flapper 77 is biased away from its receiving recess 76 it moves through access 90 sealingly engaging seat 89, closing tubing string T and preventing further flow of effluents from the well. This position is maintained as long as the hydraulic suspension apparatus is in the released position.

After normal conditions have returned to the well and repairs have been made to the well, if necessary, the valve may be opened again. This is accomplished by simply reapplying the necessary pressure to suspension apparatus 10 to cause the above portion of tubing string T and outer valve body 60 to be lifted upwardly to the position of FIG. 3. As outer valve body 60 is moved axially upward, relative to inner body 61, flapper 77 is cammed or pivoted outwardly by the edges of access 90 causing the flapper to be retracted within its receiving access 76 where it will again be maintained until subsequent release of the hydraulic suspension means 10.

One of the desirable features of a valve such as the valve 15 described in FIG. 3 is its ability to be tested. All that is necessary is to release the above portion of tubing string T, by releasing the hydraulic suspension means 10. The valve should close preventing effluent flow from the well and assuring that the valve is operative. There may be rare occasions, for some unpredictable reason, when the flapper 77 of valve 15 does not function properly, or it may be desired to use the flapper 77 of valve 15 as a secondary of standby valve closure. For these reasons a retrievable valve, generally designated at 91 in FIG. 4, may be utilized. Such a valve 91 may be adapted for axial movement through tubing string T for operative engagement with valve assembly 15 and for operation in response to relative axial movement between outer and inner tubular body members 60 and 61, respectively. The operative engagement of valve 91 with valve assembly 15 may also render flapper 77 inoperative in response to such relative axial movement.

The valve 91 includes a ball valve closure member 92 carried within a tubular ball mount body 93. The ball mount body 93 is mounted for a limited axial movement within a surrounding tubular housing 94. Housing 94 is stationarily fixed relative to the inner tubular body 61 of valve assembly 15 by the engagement of a latches 95 with latch recess 88. Latches 95 are locked in place by locking sleeve 99. Stationarly affixed to the outer tubular body 60 of valve assembly 15, by engagement of latches 96 with latch recess 75, is an actuating sleeve 97. Latches 96 are held in their radially outer locking position by a locking sleeve 98.

Prior to running valve assembly 91 into place on a wireline, locking sleeve 99 is displaced downwardly and temporarily maintained in such position by shear screw 100. In this position latches are allowed to be retracted within the receiving grooves 101. Locking sleeve 98 is initially held in an upwardly displaced position by a shear screw 102 so that latches 96 may also be retracted within receiving grooves 103. As the valve 91 is run through the tubing string T locking sleeve 99 comes into contract with stop shoulder 87. With a sufficient force applied to the upper end of valve 91, screw 100 is sheared, allowing locking sleeve 99 to move behind latches 95, locking them in place. As further weight or force is applied to the upper end of valve 91, screw 102 is sheared, allowing locking sleeve 98 to move downwardly behind latches 96, locking actuating sleeve 97 in place. When looking sleeve 99 has been moved to its locking position, a resilient metal split ring 104 is free to spring radially outwardly in a receiving groove to prevent return movement of the locking sleeve 99.

As the above portion of the tubing string T and consequently tubular body 60 and actuating sleeve 97, is moved longitudinally downwardly due to the loss of surface support, actuating sleeve 97 causes ball mount body 93 and ball closure 92 to move downwardly against the upwardly directed force of spring 105. A pin 106 carried by the tubular housing 94 projects radially inwardly through appropriate openings in the ball mount body 93 into a cam recess 107 formed along the external surface of the ball 92. Downward movement of the ball 92 forces the cam recess 107 to follow the pin 106, rotating the ball 92 to a closed position. When the surface support is reestablished and the tubing string T, moved longitudinally upwardly, the pin 106 acting against the surfaces of cam recess 107 and the spring cause the ball 92 to return to its open position. Upper and lower packing rings 108 and 109, respectively, cooperate with annular seal rings 110, 111 and 112 to maintain a leak-proof closure when the valve element 92 is rotated to a closed position.

It is well known in the industry that tubing strings may lengthen or shorten to some extent under normal well induced conditions. For example, changes in temperature and pressures within the well may cause this to occur. It can readily be appreciated that such normal well induced movements could possibly prematurely operate valves 15 and 16 (FIG. 1) or the retrievable valve 91 (FIG. 4) which might be installed in the valve. For this reason, it is desirable and sometimes necessary, to provide a system, such as the one illustrated herein, with means to compensate for such movements. The combination slip joint connectors 17 and 18 of FIG. 1 are designed for this purpose. Not only do they provide for well induced movement compensation, they may also be used to separate sections of the tubing strings T T if so desired.

FIGS. 5 and 6 illustrate a preferred embodiment of a combination slip joint connector 17 for use with the present invention. The joint 17 comprises upper and lower tubular adaptors 113, 114, respectively, for threaded connection with upper and lower sections of the tubing string T Threadedly attached to lower adaptor 114 is a tubular housing 115 provided with an internal annular latch recess 116. The lower end of upper adaptor 113 is telescopically received within tubular housing 115 and carries a set of latches 117 for engagement with latch recess 116. The particular latches illustrated in FIGS. and 6 comprise a plurality of lugs 118 mounted on finger like extensions 119 for resilient biasing toward such engagement with recess 116. The lower ends of extensions 119 may be attached to a retainer ring 120. Maintained behind the latches 117 and engaging lugs 118, to prevent their disengagement from recess 116, is a locking sleeve 121 held in place by a resilient snap ring 122 carried by retainer As can readily be seen, the longitudinal dimension of latch recess 116 is substantially greater than the longitudinal dimension of lug 118. Thus, lug 118 is allowed limited longitudinal movement within the recess 116. The disposition of lug 118 within recess 116 and its limited movement also allows limited axial movement of adaptor 113 and the section of tubing string T thereabove relative to tubular housing 115, adaptor 114 and the section of tubing string T therebelow. Such limited movement is provided to compensate for any normal well induced movements which may occur from temperature, pressure changes, etc., without prematurely operating the subsurface valves therebelow. However, upon release of support from the surface of the well, due to abnormal conditions, forces are transmitted through the tubing string T to the subsurface valves causing them to be operated. Annular seals 123, 124 and 125 assure that. no leakage occurs in the joint 15.

plished by lowering a suitable tool through the tubing string T for contact with the locking sleeve 121. With a sufficient amount of weight the snap ring 122 can be caused to expand radially for disengagement from recess 126 allowing the locking sleeve 121 to move downwardly to a point where a reduced diameter portion 127 lies adjacent to plugs 118. This position may be maintained by the reengagement of snap ring 122 with another recess 128 on the locking sleeve. In this position there is nothing to prevent lugs 118 from escaping recess 116 when an upward force is applied to tubing string T The lugs 1 18 are cammed inwardly, by mutually engageable tapered surfaces 129 and 130, allowing adaptor 113 and the section of the tubing string T thereabove to be completely separated from housing 115, adaptor 114 and the section of tubing string T therebelow, without disturbing the subsurface valves, packers, etc.

An alternative connector 131 is shown in FIG. 7. However this connector does not compensate for normal well induced movement and other means would have to be provided for this purpose. Such a connector 131 would, however, allow separation of upper and lower sections of the tubing string T The connector 131 may include upper and lower adaptors 132, 133, respectively, for connection in the tubing string T,, a tubular housing 134 and latches 135. Tubular housing 134 is provided with an annular recess 136 for engagement by latch lugs 137 carried on resilient cantilevered fingers 138. The latch lugs 137 would be held in engagement with recess 136 by locking ring 139 connected to housing 134 by shear screw 140. To release the latches 135 for disengagement from recess 136, a suitable tool would be lowered through the tubing string T for engagement with locking sleeve 139, and a force applied thereto sufficient to shear screw 140. Locking sleeve 139 would then fall downwardly from behind lugs 137 allowing them to spring inwardly on an upwardly directed force being applied to the upper sec tion of tubing string T From the foregoing description it can be seen that the assembly of the present invention offers many advantages for automatically regulating the flow of effluents through a well. The hydraulic suspension system disclosed herein is unique and especially suitable for multiple tubing well completions. The subsurface valves described herein for use with the assembly are simple but extremely efficient and trouble free in operation. The slip joint provided to compensate for normal well induced movements also serve a unique function in allowing separation of upper and lower sections of the tubing strings without distubing the subsurface valves, packers, and other equipment therebelow.

The particular emobidments disclosed and described herein exemplify the invention. However, various changes in the size, shape and materials, as well in the details of the illustrated construction, may be made by those skilled in the art without departing from the spirit of the invention. It is therefore intended that the scope I of the invention be limited only by the claims which follow.

I claim:

1. An assembly for regulating the flow of effluents through a well comprising:

a. support means releasably supporting a plurality of parallel conduits in said well;

b. sensor means connected to said support means and responsive to one or more predetermined conditions at said well to automatically release said support means; and

c. flow control means comprising valve means in each of said conduits operable upon predetermined movement of its respective conduit to regulate flow of effluents through the well, said valve means comprising a first valve connected to said conduit and a second valve adapted to be moved axially through said conduit into operative engagement with said first valve to render said first valve inoperative and said second valve operative upon said predetermined movement of its respectiveconduit.

2. An assembly as set forth in claim 1 in which said first valve is a flapper type valve and said second valve is a ball type valve.

3. An assembly as defined in claim 1 in which each of said conduits extends between said support means and an anchoring means disposed substantially below the surface of said well.

4. An assembly as defined in claim 3 further including compensating means between said support means and said valve means in each of said conduits accommodating normal well induced movement of said conduits for preventing induced movement from operating said valve means.

5. An assembly as defined in claim 4 in which said compensating means includes a connector joint releasably connecting an upper section of said conduit to a lower section of said conduit.

6. An assembly as set forth in claim 3 in which said support means comprises a tubular hydraulic piston connected to each of said conduits and mounted within a hydraulic cylinder for limited axial movement.

7. An assembly as set forth in claim 6 in which each of said hydraulic cylinders is connected to a source of pressurized fluid supporting said pistons and conduits at an upper position, said sensor means being responsive to said predetermined conditions to reduce the pressure of said pressurized fluid releasing said conduits for said predetermined movement.

8. An assembly for regulating the flow of effluents through a well comprising:

a. support means releasably supporting a plurality of conduits in said well;

b. sensor means connected to said support means and responsive to one or more predetermined conditions at said well to automatically release said support means;

0. flow control means connected to each of said conduits and operable upon predetermined movement of its respective conduit to regulate flow of effluents through the well; and i d. compensating means in each of said conduits accommodating normal well induced movement of said conduits for preventing induced movement from operating said flow control means, said compensating means including a connector joint releasably connecting an upper section of said respective conduit to a lower section of said respective conduit, said connector means comprising first and second telescopically engageable portions connected to said conduit sections, one of said portions having an annular recess engageable by latch means carried by the other of said portions.

9. An assembly as set forth in claim 8 in which said connector joint includes locking means engageable with said latch means to lock said latch means in engagement with said recess.

10. An assembly as set forth in claim 9 in which the length of said annular recess is such as to accommodate limited axial movement of said latch means during said normal well induced movement of said conduits without release of said upper and lower conduit sections.

11. An assembly as set forth in claim 10 in which said latch means comprises lug means biased toward engagement with said annular recess.

12. An assembly as set forth in claim 11 in which said locking means comprises sleeve means axially moveable from a first position, behind said lug means locking said lug means in said annular recess, to a second position, permitting disengagement of said lug means from said annular recess, to release said upper and lower conduit sections.

13. An assembly for regulating the flow of effluents through a well comprising:

a. support means releasably supporting a conduit in said well;

b. flow control means connected with said conduit and operable upon predetermined movement of said conduit to regulate the flow of effluents through said well;

c. release means included with said support means operable in response to one or more predetermined conditions at said well for releasing support of said conduit to permit said predetermined movement; and

d. connector means releasably connecting an upper section of said conduit to a lower section and accommodating normal well induced movement of said conduit for preventing induced movement from operating said flow control means, said connector means permitting removal of said upper section from said well while said lower section remains therein, said connector means comprising first and second telescopically engageable tubular portions, one of which is provided with an annular recess and on the other of which is carried latch means for engagement with said annular recess.

14. An assembly as defined in claim 13 in which said support means includes hydraulic suspension means containing hydraulic fluid and actuable in response to a predetermined reduction in pressure of said hydraulic fluid to release said conduit for axial movement under the influence of gravity to operate said flow control means to close said conduit to effluent flow.

15. An assembly as set forth in claim 13 in which said connector means comprises locking means engageable with said latch means to lock said latch means in engagement with said recess preventing separation of said upper and lower conduit sections.

16. An assembly as set forth in claim 15 in which said annular recess is of such a dimension as to permit limited axial movement of said latch means therein to accommodate said normal well induced movement.

17. An assembly as set forth in claim 16 in which said locking means comprises sleeve means axially moveable to a position permitting disengagement of said latch means from said recess and permitting separation of said upper and lower conduit sections.

18. An assembly as set forth in claim 17 in which said locking means comprises means for locking said sleeve means in said position permitting disengagement of said latch means from said recess.

19. An assembly as set forth in claim 16 in which said latch means comprises lug means affixed to a plurality of resilient finger means biasing said lug means toward engagement with said recess.

20. An assembly as set forth in claim 16 in which said flow control means comprises valve means operable upon said predetermined movement of said conduit to open or close said conduit.

21. An assembly as set forth in claim 20 in which said valve means comprises a first valve connected to said conduit and a second valve adapted to be moved axially through said conduit into operative engagement with said first valve to render said first valve inoperative and said second valve operative upon said predetermined movement of said conduit.

22. An assembly as set forth in claim 21 in which said first valve is a flapper type valve.

23. A subsurface valve assembly for use in a well conduit comprising:

a. a first tubular body connected to an upper section of said conduit at a subsurface location in said well;

b. a second tubular body connected to a lower section of said conduit, telescopically and sealingly engaging said first tubular body;

0. seat means carried by one of said tubular bodies;

d. closure means carried by the other of said tubular bodies and adapted to move betweenan open position, allowing flow through said conduit, to a closed position engaging said seat means and preventing flow through said conduit, in response to relative axial movement between said upper and lower conduit sections; and

e. a retrievable valve adapted for axial movement through said conduit for operative engagement with said first and second tubular bodies to prevent movement of said closure means to said closed position, said retrievable valve being movable between an open position and a closed position in response to said relative axial movement between said upper and lower conduit sections.

24. A subsurface valve assembly as set forth in claim 23 in which said upper section of conduit is provided with connector means accommodating normal well induced movement of said conduit for preventing said induced movement from operating said closure member.

25. A subsurface valve assembly as set forth in claim 23 in which said retrievable valve comprises a third tubular body, adapted for telescopic reception within said first tubular body; a fourth tubular body adapted for telescopic reception within said second tubular body; and second closure means, adapted to move between positions permitting and preventing flow through said conduit in response to said relative axial move ment between said upper and lower conduit sections.

26. A subsurface valve assembly as set forth in claim 25 in which said closuremember is of the ball type having a flow passage rotatable from a position in axial registration with said tubular bodies in said open position to position transverse to the axes of said tubular bodies in said closed position.

27. A subsurface valve assembly as set forth in claim 23 in which said closure means comprises a flapper member connected to pivot means for pivotal movement between said open and closed positions,

28. A subsurface valve assembly as set forth in claim 27 in which said closure means includes biasing means biasing said flapper member toward said closed position.

29. A subsurface valve assembly as set forth in claim 27 in which said one of said tubular members includes a sleeve member axially movable, in response to relative axial movement between said tubular members, between a first position preventing movement of said flapper member and a second position allowing movement of said flapper member to said closed position sealingly engaging said seat means.

30. A subsurface valve assembly as set forth in claim a 29 in which said sleeve member includes said seat seat means. 

1. An assembly for regulating the flow of effluents through a well comprising: a. support means releasably supporting a plurality of parallel conduits in said well; b. sensor means connected to said support means and responsive to one or more predetermined conditions at said well to automatically release said support means; and c. flow control means comprising valve means in each of said conduits operable upon predetermined movement of its respective conduit to regulate flow of effluents through the well, said valve means comprising a first valve connected to said conduit and a second valve adapted to be moved axially through said conduit into operative engagement with said first valve tO render said first valve inoperative and said second valve operative upon said predetermined movement of its respective conduit.
 2. An assembly as set forth in claim 1 in which said first valve is a flapper type valve and said second valve is a ball type valve.
 3. An assembly as defined in claim 1 in which each of said conduits extends between said support means and an anchoring means disposed substantially below the surface of said well.
 4. An assembly as defined in claim 3 further including compensating means between said support means and said valve means in each of said conduits accommodating normal well induced movement of said conduits for preventing induced movement from operating said valve means.
 5. An assembly as defined in claim 4 in which said compensating means includes a connector joint releasably connecting an upper section of said conduit to a lower section of said conduit.
 6. An assembly as set forth in claim 3 in which said support means comprises a tubular hydraulic piston connected to each of said conduits and mounted within a hydraulic cylinder for limited axial movement.
 7. An assembly as set forth in claim 6 in which each of said hydraulic cylinders is connected to a source of pressurized fluid supporting said pistons and conduits at an upper position, said sensor means being responsive to said predetermined conditions to reduce the pressure of said pressurized fluid releasing said conduits for said predetermined movement.
 8. An assembly for regulating the flow of effluents through a well comprising: a. support means releasably supporting a plurality of conduits in said well; b. sensor means connected to said support means and responsive to one or more predetermined conditions at said well to automatically release said support means; c. flow control means connected to each of said conduits and operable upon predetermined movement of its respective conduit to regulate flow of effluents through the well; and d. compensating means in each of said conduits accommodating normal well induced movement of said conduits for preventing induced movement from operating said flow control means, said compensating means including a connector joint releasably connecting an upper section of said respective conduit to a lower section of said respective conduit, said connector means comprising first and second telescopically engageable portions connected to said conduit sections, one of said portions having an annular recess engageable by latch means carried by the other of said portions.
 9. An assembly as set forth in claim 8 in which said connector joint includes locking means engageable with said latch means to lock said latch means in engagement with said recess.
 10. An assembly as set forth in claim 9 in which the length of said annular recess is such as to accommodate limited axial movement of said latch means during said normal well induced movement of said conduits without release of said upper and lower conduit sections.
 11. An assembly as set forth in claim 10 in which said latch means comprises lug means biased toward engagement with said annular recess.
 12. An assembly as set forth in claim 11 in which said locking means comprises sleeve means axially moveable from a first position, behind said lug means locking said lug means in said annular recess, to a second position, permitting disengagement of said lug means from said annular recess, to release said upper and lower conduit sections.
 13. An assembly for regulating the flow of effluents through a well comprising: a. support means releasably supporting a conduit in said well; b. flow control means connected with said conduit and operable upon predetermined movement of said conduit to regulate the flow of effluents through said well; c. release means included with said support means operable in response to one or more predetermined conditions at said well for releasing support of said conduit to permit said predetermined movement; and d. connector means releasably connecting an upper section of said conduit to a lower section and accommodating normal well induced movement of said conduit for preventing induced movement from operating said flow control means, said connector means permitting removal of said upper section from said well while said lower section remains therein, said connector means comprising first and second telescopically engageable tubular portions, one of which is provided with an annular recess and on the other of which is carried latch means for engagement with said annular recess.
 14. An assembly as defined in claim 13 in which said support means includes hydraulic suspension means containing hydraulic fluid and actuable in response to a predetermined reduction in pressure of said hydraulic fluid to release said conduit for axial movement under the influence of gravity to operate said flow control means to close said conduit to effluent flow.
 15. An assembly as set forth in claim 13 in which said connector means comprises locking means engageable with said latch means to lock said latch means in engagement with said recess preventing separation of said upper and lower conduit sections.
 16. An assembly as set forth in claim 15 in which said annular recess is of such a dimension as to permit limited axial movement of said latch means therein to accommodate said normal well induced movement.
 17. An assembly as set forth in claim 16 in which said locking means comprises sleeve means axially moveable to a position permitting disengagement of said latch means from said recess and permitting separation of said upper and lower conduit sections.
 18. An assembly as set forth in claim 17 in which said locking means comprises means for locking said sleeve means in said position permitting disengagement of said latch means from said recess.
 19. An assembly as set forth in claim 16 in which said latch means comprises lug means affixed to a plurality of resilient finger means biasing said lug means toward engagement with said recess.
 20. An assembly as set forth in claim 16 in which said flow control means comprises valve means operable upon said predetermined movement of said conduit to open or close said conduit.
 21. An assembly as set forth in claim 20 in which said valve means comprises a first valve connected to said conduit and a second valve adapted to be moved axially through said conduit into operative engagement with said first valve to render said first valve inoperative and said second valve operative upon said predetermined movement of said conduit.
 22. An assembly as set forth in claim 21 in which said first valve is a flapper type valve.
 23. A subsurface valve assembly for use in a well conduit comprising: a. a first tubular body connected to an upper section of said conduit at a subsurface location in said well; b. a second tubular body connected to a lower section of said conduit, telescopically and sealingly engaging said first tubular body; c. seat means carried by one of said tubular bodies; d. closure means carried by the other of said tubular bodies and adapted to move between an open position, allowing flow through said conduit, to a closed position engaging said seat means and preventing flow through said conduit, in response to relative axial movement between said upper and lower conduit sections; and e. a retrievable valve adapted for axial movement through said conduit for operative engagement with said first and second tubular bodies to prevent movement of said closure means to said closed position, said retrievable valve being movable between an open position and a closed position in response to said relative axial movement between said upper and lower conduit sections.
 24. A subsurface valve assembly as set forth in claim 23 in which said upper section of conduit is provided with connector means accommodating normal well induced movement of said conduit for preventing said induced movement from operating said closure member.
 25. A subsurface valve assembly as set forth in claim 23 in which said retrievable valve comprises a third tubular body, adapted for telescopic reception within said first tubular body; a fourth tubular body adapted for telescopic reception within said second tubular body; and second closure means, adapted to move between positions permitting and preventing flow through said conduit in response to said relative axial movement between said upper and lower conduit sections.
 26. A subsurface valve assembly as set forth in claim 25 in which said closure member is of the ball type having a flow passage rotatable from a position in axial registration with said tubular bodies in said open position to position transverse to the axes of said tubular bodies in said closed position.
 27. A subsurface valve assembly as set forth in claim 23 in which said closure means comprises a flapper member connected to pivot means for pivotal movement between said open and closed positions.
 28. A subsurface valve assembly as set forth in claim 27 in which said closure means includes biasing means biasing said flapper member toward said closed position.
 29. A subsurface valve assembly as set forth in claim 27 in which said one of said tubular members includes a sleeve member axially movable, in response to relative axial movement between said tubular members, between a first position preventing movement of said flapper member and a second position allowing movement of said flapper member to said closed position sealingly engaging said seat means.
 30. A subsurface valve assembly as set forth in claim 29 in which said sleeve member includes said seat means and an aperture through which said flapper member moves for said sealing engagement with said seat means. 